optics - What's the history of neutral density filters instead of aperture diaphragms in compact cameras?

Some compact cameras use neutral density filters to control light rather than aperture blades, to avoid the effects of diffraction in tiny sizes.

I first heard of this as a feature of the Nokia N8 cameraphone, which emphasizes photography as a main selling point. But are there earlier cameras exhibiting this feature? How common is it? What other current models work this way?

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_{This is a second question inspired by this answer to an earlier question.}